With increasingly requirements for mobile data services, most low-frequency band spectrum resources applicable to mobile communication have been allocated (for example, a frequency band lower than 3 GHz), but in a frequency band of 3 to 300 GHz, a large quantity of spectrum resources have not been allocated for use. According to a definition of the International Telecommunication Union (ITU), a frequency band of 3 to 30 GHz is referred to as a super high frequency (SHF) frequency band, and a frequency band of 30 to 300 GHz is referred to as an extremely high frequency (EHF) frequency band. Because the SHF and EHF frequency bands have a similar transmission feature, for example, a transmission loss is relatively large, and a wavelength ranges between 1 millimeter and 100 millimeters, the frequency band of 3 to 300 GHz is also collectively referred to as a millimeter wave frequency band. At present, research of applying the millimeter wave frequency band to cellular mobile communication is still at an initial stage, a technology is not mature, and many difficulties still remain to be overcome.
In an existing implementation solution, a high-speed data service is provided by using a millimeter wave frequency band, a millimeter wave base station is deployed within coverage of a cellular base station, and a user equipment needs to measure a cellular frequency band to access the cellular base station; in addition, the user equipment further needs to measure the millimeter wave frequency band except the conventional cellular frequency band to access the millimeter wave base station. Even though the user equipment is not within coverage of any millimeter wave base station, the user equipment still needs to continually perform inter-frequency cell search and measurement, which inevitably quickens consumption of battery power of the user equipment, and causes unnecessary waste. Similarly, when the millimeter wave base station serves no user, the millimeter wave base station still needs to continually transmit a measurement signal and a pilot signal, which also wastes power on the millimeter wave base station side, further causes pilot pollution, and causes interference to another millimeter wave base station around, thereby decreasing a system throughput.